Seiko Cal. 6637 - 691

The Seiko 6637-691 represents an important milestone in Seiko's 1978 lineup. Powered by the 6637 caliber with 22j jewels beating at 21,600 bph, it delivers a 62 hours power reserve. [seikata-wm-bb78db1bd1f4]

Also known as: Goldfeather, Crown

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

40mm

Case Thickness

12.6mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

160m

Dial Color

Cream

Jewels

22j

Frequency

21,600 bph

Power Reserve

62 hours

Year

1978

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